Over the past several years, liquid metal nuclear reactors for commercial production of nuclear power have been under development. Typically, economies of scale drive new nuclear plant configuration toward large, standalone structures. Commercialization of new reactor technology such as liquid metal reactors usually depends on a stepwise demonstration of isolated plant systems at a reduced scale, followed by scale-up to a fully-integrated, large-scale commercial plant. However, stepwise demonstration and testing of plant systems is a costly and time-consuming process. It would be desirable to provide a liquid metal reactor plant configuration of reduced scale which would reduce the cost, risk and time required for full scale testing and demonstration of fully-integrated liquid metal reactors. It would also be desirable to provide a modular liquid metal reactor plant configuration to facilitate liquid metal reactor plant scale-up.
Known modular liquid metal reactor plant configurations exist, but are limited in that they do not provide for seismic isolation of the whole reactor power block and the supporting liquid metal facilities. In one such configuration the refueling process requires the nuclear reactors to be located in underground silos so that seismic isolation is achieved only for the reactors, and only then for the reactors as individual units. Further, seismic isolation is achieved with the use of complicated pipe systems for the liquid metal and process gases, and with isolation gaps around individual reactor modules. In such known plant configurations, a seismic disturbance may still be communicated substantially through the reactor systems, multiplying the damaging effects with potentially disastrous results. The utilization of underground reactor silos, isolation gaps and complicated pipe systems also substantially increases the size, complexity and costs of the reactor plants. It would be desirable to provide a simple and compact modular liquid metal reactor plant configuration with improved seismic isolation. It would be further desirable to provide such a configuration as a substantially above ground structure.
In addition, known modular plant configurations are limited by the requirement that containment structures be able to bear high containment pressure loads. The metal domes used for containment in known modular plant configurations are costly, complicated, and interfere with access for reactor maintenance. It would be desirable to provide a modular liquid metal reactor plant configuration which reduces the requirements and cost of the containment structure by reducing the containment pressure load. It would be further desirable to provide such a reactor plant configuration with access space for maintenance, repair and replacement of reactor components.